public static ref BlockMatrix <N, T> Mul <N, T>(BlockMatrix <N, T> A, BlockMatrix <N, T> B, ref BlockMatrix <N, T> X)
where N : ITypeNat, new()
where T : unmanaged
{
var n = nati <N>();
for (var i = 0; i < n; i++)
{
for (var j = 0; j < n; j++)
{
X[i, j] = dot(A.Row(i), B.Col(j));
}
}
return(ref X);
}
/// Evaluates whether a square matrix is right-stochasitc, i.e. the sum of the entries
/// in each row is equal to 1
/// </summary>
/// <param name="src">The matrix to evaluate</param>
/// <param name="n">The natural dimension value</param>
/// <typeparam name="N">The natural dimension type</typeparam>
/// <typeparam name="T">The element type</typeparam>
public static bool IsRightStochastic <N, T>(this BlockMatrix <N, T> src, N n = default)
where N : ITypeNat, new()
where T : struct
{
var tol = .001;
var radius = closed(1 - tol, 1 + tol);
for (var r = 0; r < (int)n.value; r++)
{
var row = src.Row(r);
var sum = convert <T, double>(mathspan.sum(row.Unsized));
if (!radius.Contains(sum))
{
return(false);
}
}
return(true);
}
